oj.uz

답안 #958480

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
958480 2024-04-05T21:14:59 Z BhavayGoyal Olympic Bus (JOI20_ho_t4) C++14
5 / 100
 80 ms 7760 KB 
#include <bits/stdc++.h>
using namespace std;

#define int long long
#define vi vector<int>
#define vii vector<vector<int>>
#define pii pair<int, int>
#define pb push_back
#define f first
#define s second
#define endl "\n"

const int linf = 1e15;

// -------------------------------------------------- Main Code --------------------------------------------------

const int N = 201, M = 50001;
int n, m;
set<pii> g[N];
vii edges;
map<pair<int, int>, bool> isShort;

void dijkstra(int source) {
    priority_queue<pii, vector<pii>, greater<>> q;
    vi vis(n+1, 0), dis(n+1, linf), par(n+1);
    q.push({0, source});
    dis[source] = 0;
    while (!q.empty()) {
        pii f = q.top(); q.pop();
        int src = f.s;
        if (vis[src]) continue;
        vis[src] = true;

        for (auto child : g[src]) {
            int ch = child.f, wt = child.s;
            if (dis[ch] > dis[src] + wt) {
                par[ch] = src;
                dis[ch] = dis[src] + wt;
                q.push({dis[ch], ch});
            }
        }
    }

    int x = (source==1?n:1);
    while (par[x]) {
        isShort[{par[x], x}] = true;
        x = par[x];
    }
}

int get_dist(int s, int t) {
    vi D(n+1, linf);
    priority_queue<pii, vector<pii>, greater<pii>> pq;
    D[s] = 0;
    pq.emplace(0, s);
    while (pq.size()) {
        pii temp = pq.top(); int x = temp.f, u = temp.s;
        pq.pop();
        if (D[u] == x) {
            for (pii child : g[u]) {
                int v = child.f, wt = child.s;
                if (D[v] > x + wt) {
                    pq.emplace(D[v] = x + wt, v);
                }
            }
        }
    }
    return D[t];
}


void sol() {
    cin >> n >> m;
    vii dist(n+1, vi(n+1, linf));
    for (int i = 1; i <= n; i++) dist[i][i] = 0;

    for (int i = 1; i <= m; i++) {
        int a, b, c, d; cin >> a >> b >> c >> d;
        dist[a][b] = min(dist[a][b], c);
        g[a].insert({b, c});
        edges.pb({a, b, c, d});
    }

    dijkstra(1);
    dijkstra(n);
    
    for (int k = 1; k <= n; ++k) {
        for (int i = 1; i <= n; ++i) {
            for (int j = 1; j <= n; ++j) {
                dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);
            }
        }
    }

    int ans = min(linf, dist[1][n] + dist[n][1]);

    for (auto i : edges) {
        int a = i[0], b = i[1], c = i[2], d = i[3];
        if (isShort[{a, b}]) {
            g[a].erase({b, c});
            g[b].insert({a, c});
            ans = min(ans, get_dist(1, n) + get_dist(n, 1) + d);
            g[b].erase({a, c});
            g[a].insert({b, c});
        }
        else {
            int A = min(dist[1][n], dist[1][b] + c + dist[a][n]);
            int B = min(dist[n][1], dist[n][b] + c + dist[a][1]);
            if (A < linf && B < linf) {
                ans = min(ans, A + B + d);
            }
        }
    }

    cout << (ans==linf?-1:ans) << endl;
}

signed main () {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int t = 1;
    // cin >> t; 
    while (t--) {
        sol();
    }
    return 0;
}

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 9 ms 856 KB Output is correct
2 Correct 7 ms 604 KB Output is correct
3 Correct 8 ms 860 KB Output is correct
4 Correct 9 ms 860 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 7 ms 604 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 13 ms 604 KB Output is correct
10 Correct 23 ms 980 KB Output is correct
11 Correct 30 ms 856 KB Output is correct
12 Correct 29 ms 1124 KB Output is correct
13 Correct 8 ms 936 KB Output is correct
14 Correct 8 ms 860 KB Output is correct
15 Correct 8 ms 936 KB Output is correct
16 Correct 9 ms 860 KB Output is correct

Subtask #2
0 / 11.0

# 결과 실행 시간 메모리 Grader output
1 Correct 80 ms 6784 KB Output is correct
2 Correct 62 ms 6812 KB Output is correct
3 Correct 68 ms 6920 KB Output is correct
4 Incorrect 9 ms 860 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# 결과 실행 시간 메모리 Grader output
1 Correct 8 ms 860 KB Output is correct
2 Correct 7 ms 604 KB Output is correct
3 Correct 41 ms 6620 KB Output is correct
4 Correct 8 ms 604 KB Output is correct
5 Correct 52 ms 7760 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 40 ms 7180 KB Output is correct
9 Correct 44 ms 7088 KB Output is correct
10 Correct 43 ms 6408 KB Output is correct
11 Correct 40 ms 6492 KB Output is correct
12 Correct 43 ms 6408 KB Output is correct
13 Incorrect 0 ms 348 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# 결과 실행 시간 메모리 Grader output
1 Correct 9 ms 856 KB Output is correct
2 Correct 7 ms 604 KB Output is correct
3 Correct 8 ms 860 KB Output is correct
4 Correct 9 ms 860 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 7 ms 604 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 13 ms 604 KB Output is correct
10 Correct 23 ms 980 KB Output is correct
11 Correct 30 ms 856 KB Output is correct
12 Correct 29 ms 1124 KB Output is correct
13 Correct 8 ms 936 KB Output is correct
14 Correct 8 ms 860 KB Output is correct
15 Correct 8 ms 936 KB Output is correct
16 Correct 9 ms 860 KB Output is correct
17 Correct 80 ms 6784 KB Output is correct
18 Correct 62 ms 6812 KB Output is correct
19 Correct 68 ms 6920 KB Output is correct
20 Incorrect 9 ms 860 KB Output isn't correct
21 Halted 0 ms 0 KB -